The influence of pH-ultrasonic-induced myofibrillar protein conformation of Penaeus vannamei (Litopenaeus vannamei) on emulsification and digestion characteristics of fish oil oleogel-based emulsions.

pH-induced and ultrasound treatment can both adjust spatial conformation to improve the interfacial stability, and fish oil oleogel could be used to enhance oil binding capacity. The relationship between stabilization mechanism and lipid digestion was revealed, considering the protein conformation and interfacial characteristics. The results showed that pH-ultrasonic-induced myofibrillar proteins (MPs) at pH 7.0 had higher interfacial adsorption capacity and surface hydrophobicity as well as more stable secondary structures, which lowered the particle size and enhanced the interfacial stability. In the stomach, the particle size increased along with the decrease in electrostatic repulsion, and β-sheets significantly increased, which promoted aggregation and flocculation. In the small intestine, the reduction of β-sheets favored the interfacial replacement and facilitated the lipid digestion. Therefore, pH-ultrasonic-modified method improved the structure and function of MPs, facilitated the interfacial stability and intestinal digestion.